Tuesday, 3 February 2015

When It Comes to Jogging, Easy Does It, Study Suggests

Just an hour or two a week confers life-extension benefits, researcher contends

WebMD News from HealthDay

By Kathleen Doheny

HealthDay Reporter

MONDAY, Feb. 2, 2015 (HealthDay News) -- A little jogging is good for your health, researchers say, but too much might not be.

"In this study, the dose of running that was most favorable for reducing mortality was jogging 1 to 2.4 hours per week, with no more than three running days per week," said study researcher Jacob Marott of the Frederiksberg Hospital in Copenhagen, Denmark. The best pace was slow or average -- about 5 miles per hour, he added.

Out of a pool of about 5,000 healthy Danish adults, Marott and his colleagues followed nearly 1,100 healthy joggers and 413 sedentary people for more than 12 years. The joggers noted their hours and frequency of jogging, and their perception of their pace.

The strenuous joggers, the investigators found, were as likely to die during that time period as the sedentary non-joggers. Light joggers and moderate joggers fared better, in that order, Marott's team found.

The findings were released online Feb. 2 in advance of publication in the Feb. 10 print edition of the Journal of the American College of Cardiology.

What is it about strenuous running that might be harmful? "We believe that long-term strenuous endurance exercise may induce pathological structural remodeling of the heart and large arteries," Marott said.

However, a U.S.-based researcher said the debate about the optimal dose of running for longevity is far from resolved.

The new study has limitations, said D.C. (Duck-chul) Lee, an assistant professor of kinesiology at Iowa State University, who co-authored an editorial accompanying the study.

In Lee's own study of 55,000 adults, including more than 13,000 runners, he found a lower risk of death over the follow-up period in joggers with the highest running time and frequency -- nearly three hours a week and at least six times a week -- compared with non-runners. It was published in 2014, also in the Journal of the American College of Cardiology.

In the Copenhagen study, joggers self-reported their pace. Even the slow joggers were getting vigorous exercise, the researchers said.